Installing DWV system new construction

Hi All:

I am in the process of installing the DWV system in our house that I am building. The house if framed and the outside is all done. I have 2 - 3" vents poked out of the roof and there is a 4" septic pipe in the basement leading out to the tank and division box then into the drain field.

I think I am going over board with this installation and would appreciate any comments and suggestions. I have calculated the drain units as well as the fixture units and have decided to run separate 2" vent lines for each trap which connect as close as possible to the trap. All these vents which is a total of 12 will all tap into a 3" header that will run across the attic via sanitary "T"s. At each end of the 3" header I will install a "T" with a clean out and tie each end into the 3" pipe that is poked through the roof.

As for the drain all the drains run into the basement and I will install a clean out "T" for each drain then plumb it into the 4" header with sanitary "T"s. This 4" header will terminate into the septic pipe. I will also be installing a 3" vent from this 4" drain header to the 3" vent header.

So there it is. I think I might have over designed things. Okay l appreciate your comments and suggestions and the time to respond.
Sincere Thanks
Joe

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Installing DWV system new construction

Hi Bill:

The inspector loves it! I want to be sure to do a good job with this installation. I also wanted to know what my peers think!

I attended a night class on plumbing which was helpful. I then purchased some books which were also helpful and away I went. As I'm doing the work I am coming up with all kinds of questions so I dip into the books and make sure I understand the intent and go from there. There is one thing I am not 100% sure of and thats cleanouts. I will be installing a cleanout at the bottom of each drain pipe before it goes into the drain header or should they be positioned as close to the trap as possible? Naturally I would not put a cleanout in the finished areas.